Patent GB-669312-A (GB)
Title: Sulfonated aryl alkane detergents and process of producing same
IPC: C07C309/31
Filed: 1948-10-06
Abstract: In a process for the production of a sulphonated aryl alkane p detergent from a cracked petroleum naphtha boiling within the range 300 DEG  to 600 DEG  F., the said cracked fraction is passed through a mass of a solid adsorbent, e.g. silica gel, silica-alumina, and charcoal, to separate an adsorbate and a periolate and the fraction of the percolate which has flowed from the adsorbent until the bromine number of the effluent percolate reaches approximately its maximum value is separated and then used to alkylate a mononuclear aromatic hydrocarbon such as benzene or toluene.  Alternatively the alkylation may be effected with that portion of the said separated fraction obtained after the bromine number begins to rise.  A sulphonated phenyl alkane is thus produced by subjecting a cracked petroleum oil fraction boiling under normal pressure between 300 DEG and 600 DEG  F. to silica gel adsorption treatment by passing said fraction through a column of silica gel, selecting for further treatment a fraction obtained by rejecting from said cracked petroleum fraction the portion passing from the silica gel adsorption having zero bromine number and also the portion passing from the silica gel adsorbent obtained after the bromine number has passed the maximum value on said adsorption treatment, alkylating benzene with the fraction so selected to form a phenyl alkane and sulphonating said phenyl alkane.  All or a part of the hydrocarbons exhibiting zero bromine number may however be included in the fraction selected for the alkylation treatment.  The alkane portion of the molecule generally contains between 8 and 20 carbon atoms but it is desirable to subject to the adsorption treatment a fraction boiling between 350 DEG  and 500 DEG  F. at atmospheric pressure in which about 95 per cent by volume of the olefinic materials will contain between 12 and 15 carbon atoms.  The cracked fraction used as starting material contains aliphatic and cycloaliphatic hydrocarbons and some aromatics as well as olefinic hydrocarbons and the fraction selected for alkylation generally amounts to about 30 per cent of the cracked hydrocarbon fraction starting material.  The alkylation is effected by means of a FriedelCrafts type condensation catalyst, e.g. AlCl3, H2SO4, HF, BF3, or mixtures of BF3 and HF, hydrogen fluoride being preferred.  The adsorbent treatment may be carried out by the addition of a diluent or an eluant.  The diluent added may be a lower boiling-point oil which may be readily separated from the desired olefin fraction after treatment.  In an example, a cracked naphtha fraction boiling between 350 DEG  and 500 DEG  F. is passed through a steel column containing silica gel.  The first 30 per cent of the material passing through shows a substantially zero bromine number. The bromine number then rises to a maximum and then drops rapidly. Of the material passing through the column the first 32.5 per cent is rejected and the succeeding fraction up to the 60.6 per cent portion is selected for alkylation.  This fraction, which is 28.1 per cent of the cracked naphtha starting material, contains about 30 per cent unsaturated compounds, is then used to alkylate benzene using hydrogen fluoride as catalyst and at a temperature of 100 DEG  F. The alkylation product is then distilled to separate the phenyl alkane fraction which is then sulphonated preferably with fuming sulphuric acid at 130 DEG  to 140 DEG  F.  The product is then neutralised with sodium hydroxide to form a mixture of sodium sulphonates and sodium sulphate.  The results obtained from this example are contrasted with the results obtained when the entire cracked naphtha stock was subjected to a similar treatment of alkylation and subsequent sulphonation, the results showing an increase in the efficiency as detergents for cotton of the sulphonated products obtained by using the fraction resulting from the adsorption treatment.  Specification 656,834 and U.S.A. Specification 2,275,312 are referred to.  The Specification as open to inspection under Sect. 91 states that part of the fractions passing through the column after the bromine number has reached its maximum value may be included in the material to be processed.  This subject-matter does not appear in the Specification as accepted.